608 
B M5 

py 1 



.OSSES TO COTTON 



What to Look For 

and 

Where to Find It 



Being one of a series of articles in relation to crops, their common 
diseases, and insect pests to which thev are subject 




Published by 
HAIL DKPARTMENT 

Western Adjustment &. Inspection Co. 
CHICAGO 



LOSSES TO COTTON 



LOSSES TO COTTON 



What to Look For 

and 

Where to Find It 



Being one of a series of articles in relation to crops, their common 
diseases and insect pests to which they are subject 




Pul)lislied by 
HAIL DEPARTMENT 

Western Adjustment & Inspection Co. 

CHICAGO 



o 



^^ \IVO 



Copyright, 1919, W. E. Mariner 



©CI.A5l5aH 



Stroniberft, Allen & Co., Chicago. 
Printers 

1 I lL ^ -J ' 1 



COTTON 

The raw material of our most im- 
portant maniifacturino- enterprises 
and export trade, the nature and 
special characteristics of its growth. 



'Knowledge directeth practice and 
practice increaseth knowledge." 



INTRODUCTORY 

Cotton furnishes the raw material for one of our most 
important manufacturing industries, and from one-fourth 
to one-tliird of our total exports. 

Its economic importance is far beyond numerical ex- 
pression, for, while the total crop of the world is ap- 
proximately ascertainable, the effect of cotton upon the 
commercial and social relations of mankind is too far- 
reaching for estimation. Of the four great staples that 
provide man with clothing — cotton, silk, wool and flax — cot- 
ton, by reason of its cheapness and its many excellencies 
is rapidly superseding its several rivals. Fifty years ago, 
only about 2,500,000 bales of cotton, or less than the present 
production of Texas, were annually couA'erted into clothing. 

Cotton stands pre-eminent among farm crops in the 
ease and cheapness of its production as compared with the 
variety and value of its products. It is less subject to the 
ravages of insects than any other of the staple crops, and 
no crop makes so slight a drain u]ion the fertility of the soil. 

Modern enterprise has found more uses for the several 
parts of the cotton plant than have been discovered in any 
other farm crop. The cotton plant produces, in fact, a 
double crop: (1) a most beautiful fiber and (2) seed — yield- 
ing both oil and feed — which, although neglected for a long- 
time, is now valued at one-fourth as much as the raw cotton. 
In addition to this, the stems are made to yield a liber, which 
waits only for a machine to work it, and the roots yield a 
drug. 



PART I 

INSECTS 

There are many insects wliicli derive their food from 
the cotton plant, Tliis list as a whole comprises about 4G5 
species. But a small i)ortion of these, however, can be con- 
sidered as injurious to cotton, and still fewer numbers have 
attracted the attention of cotton-planters by their injuries 
to the cro]). Many of them are enemies of, and prey upon, 
species which damage the i)lant, while many others are 
accidental visitors to tlie cotton fields and might have been 
found as readily in the fields of corn or in other crops in 
the same general localitv. 



?:>" 



The Cutworm 

The first insect to attack the young cotton plant in tlie 
spring is the cutworm. Soon after the young i)lants come 
up and often after they are fairly well grown, they are 
likelv to be cut off at tlie surface of the ground bv one of 




THE COTTON CUTW0R:\I 

Adult and larva. Natural size. 

these cateri)inars, all of which liave tlie habit of hiding be- 
neath the surface of the ground during the day and coming 
out to work at night. The granulated cutworm is probably 
the most connnon of the species and is known as the cotton 



cutworm. A number of other species of cutworms are un- 
doubtedly concerned in the damage, however. 

The Boll Weevil 

The adult boll weevil is about one-quarter of an inch 
in length, varying from one-eighth to one-third of an inch, 
with a breadth of aliout one-third of the lenu'th. This 




THE COTTON BOLL WEEVIL 

(fl) adult beetle; (h) pupa; {c) larva. Enlarged. 

measurement includes the snout, which is about one-half the 
length of the body. The color (grayish or brownish) de- 
pends upon the time that may have elapsed after trans- 




COTTON BOLL WEEVIL 

Late fall boll, showing how beetles hide between boll and inclosure. 

formation to the adult stage. The recently emerged in- 
dividuals are light yellowish in color, but pass to a gray or 
nearlv black shade in a few weeks' time. 



In the field tlie most conspienons indication of the 
presence of the boll weevil is the flaring and falling of great 
numbers of squares. However, unfavorable climatic con- 
ditions and careless cultivation fre(]uently cause much 
shedding. If excessive shedding be noticed and the squares 
upon being cut open show a white, curved grub that has fed 
upon the contents, there is little doubt that the l)oll weevil 
is the insect causing the damage. 

The boll weevil passes the winter in the adult stage. 
In the spring and throughout the fruiting season of cotton 
the eggs are deposited by the female weevils in the cavities 
formed by eating into the fruit of the plant. 

The squares are greatly i)referred as food and as places 
for depositing eggs. As long as a large supply of s(juares 
is present the bolls are not damaged to any serious extent. 




COTTON BOLL WEEVIL 

Mature boll cut open at left, showing full-grown larva; the one at the right not 
cut, and showing feeding punctures and oviposition marks. 

The bolls, therefore, have a fair chance to develop as long 
as squares are being formed. Whenever frost or other un- 
favorable weather causes the plants to cease putting on 
squares, the weevils attack the bolls. 

The cotton boll weevil, so far as known at present, 
has no food plant other than cotton. 

In the fall when frosts occur, immature stages of de- 
velopment of the boll weevil may be found in the scjuares or 
bolls. Provided food supply is sufficient, many of these 
immature stages continue their development at a very slow 
rate and adults finally emerge. Thus there may be a some- 
what continuous ])roduction of adults during the winter. 

10 



Ordinarily, however, this is not conspicuously the case, since 
the frosts that destroy the cotton generally kill practically 
all of the immature stages of the weevil. 

The Cotton Boll Worm, or Com Ear Worm 

The boll worm is the common greenish or brownish 
worm that eats into the bolls of cotton and the ears of both 
field and sweet corn. Its eggs are usually laid in the top of 




TRANSFORMATION OF COTTON BOLL WORM 

(1) Egg on underside of cotton leaf; (2) larva one-third grown boring into square; 

(3) entrance hole of young larva in square, with excremental pellets at edge 

of hole; (4) nearly full-grown larva just issued from boll; (5) full-grown 

larva on leaf stem; (6) pupa shown in center of underground earthen 

cell; cell shown in longitudinal section; (7) adult moth, light 

variety; (8) adult moth with light fore-wings; (9) adult 

moth in resting position, wings slightly elevated, hind 

border of hind wings slightly showing. 

the boll, and the young larva soon begins to feed, eating 
into the cotton at the tip of the boll. As it grows it tunnels 
down into the boll, burrowing only a part of the lock, yet 
injuring the whole fiber. 

1] 



The boll worm spends the winter in the pupa state in 
the ground. Sometimes in late spring, in May or June, the 
adnlt moths emerge and deposit their eggs on the cotton 
and corn. 

Mature larva measure about one and one-half inches 
in length. The moth, a rather stout insect, measures three- 
fourths of an inch in length. The larvae vary in color from 
light green to lu'own, being more or less striped in appear- 
ance, with alternating light and dark lines. 

The Cotton Leaf Worm, the Cotton Army Worm or 
Cotton Caterpillar 

The cotton caterpillar, the cotton army worm or cot- 
ton leaf worm, a slender, bluish-green caterpillar with 
small, black spots and often with black stripes down its 
back, which loops when it crawls and feeds voraciously on 
both upper and under surfaces of the cotton leaf, is to be 
found in cotton fields in the Gulf states all through the 
summer. It is generally unnoticed in the early part of the 
season on account of the insignificance of its number. 
Later, through the ragging of the leaves, it becomes notice- 
able, and in seasons of abundance the cotton plant is en- 
tirely defoliated. Farther north the insect makes its ap- 
pearance later in the season, and there the caterpillars are 
not the otfspring of the hibernating moths, but of the moths 
of the first or second generations, which have developed 
in cotton fields farther south and have flown north with 
the prevailing southern winds. There is no absolute evi- 
dence of these insects having any other food plants than 
cotton, although many entomologists have suspected that 
the species have a northern host plant. 

The egg is bluish-green in color and of a different 
shade from that of the leaf, so that it can be readily dis- 
tinguished. It is flattened, convex in shape, with many 
parallel, longitudinal ridges converging at the center above. 
It is found usually on the under side of the leaves and, as a 
general thing, toward the top of the plant. As many as 
five hundred eggs are laid by each female, sometimes 
several upon one leaf, but never in clusters. The eggs are 
laid at night, since the moth is a night flyer. In mid-sum- 
mer the larva hatches in from three to four days after the 
egg is laid, but in spring and autumn this period is very 

12 



considerably lengthened. After hatching from the egg, the 
young larva feeds at tirst npon the nnder side of the leaf, 
devouring simply the lower part and not i^assing through 
to the upper side until after the first molt. At first the 
larva is pale yellow in color, but soon becomes greenish. 

Before reaching full growth, the caterpillar sheds its 
skin fi^'e times, the duration of the caterpillar stage being 
from one to three weeks Early in the season the green 




THE SMARTWEED CATERPILLAR 

(a) larva; (b) cocoon; (c) adult. Natural size. 

color apjjears to |)redominate, while toward fall the black- 
ish cateri)illars are more abundant, although at any time 
during the season green and dark worms are seen together. 
Although the normal food of the caterpillar is the leaves, it 
will frequently gnaw the tender twigs, but will very rarely 
damage the bolls by eating into them, and then only in 
spots. This contingency, however, generally occurs only 
when the worms are present in excei)tional numbers and 
the supply of leaves becomes exhausted. It is somewhat 
of a cannibal and, when other food fails, or even rarely 
when, leaves are abundant, it will feed ui)on smaller and 
weaker individuals of its own kind. In spite of its com- 
paratively small size and slender form, this larva is un- 
usually greedy and when occurring in numbers, completely 
ruins the cotton crop. 

13 



It spins a light silken web, forming an imperfect 
cocoon, nsually within a folded leaf. It is freqnently seen 
hanging quite naked u])on the plant, bnt in such cases the 




THE ZEBRA CATERPILLAR 

(a) larva; (b) adult. Natural size. 

leaf in which it was originally spun has been eaten away 
by other caterpillars. 

Leaf -Feeding Caterpillars 

There are many species of larva which feed upon the 
leaves of the cotton plant. Few of these, however, are 
strictly confined to this plant for food. One of the most 




LEAF ROLLER 

1 Caterpillar; 2 moth; 3 pupa. 

14 



commonly noted is known, from its work, as the leaf roller, 
a title under wliieli another species may also be included. 
Both species are general feeders and are fonnd in various 
parts of the country, the former upon apple, peachy cherry, 
clover, honeysuckle, beans, strawberries, and other plants, 
and the latter ui)on clover and grass. The larva of the 
former, in addition to the folding of the leaves of cotton 
and feeding within the roll, sometimes bore into the young- 
bolls, although this method of damage is rare. 

The royal horn caterpillar, sometimes known as the 
hickory horn devil, a very large, green caterpillar with 
long recurved red horns, the large green, somewhat hairy 
larva of the imperial moth and the large spiny larva, also 
feeds upon cotton. The results of the work of these differ- 
ent species are identical. Two bag worms are also occa- 
sionally found feeding upon cotton leaves, constructing 
their cases from fragments of the leaves sewed together 
with silk. These are the common bag worm of the north. 

Insects Injuring the Boll 

Numerous species of insects are found in damaged 
liolls which are the results rather than the cause of the 




THE RED BUG OR COTTON STAINER 

(a) pupa; (6) adult. Enlarged. 

15 



damage. There is a class of damage to the bolls which is 
known to i»lantei's as sharp-shooter work, which is mainly 
caused by the ininctnres of a leaf hopper. This insect 
is most abnndant from the first of Jnne on through the 
season. Prior to the first of June it seems to prefer the 
young growth and foliage of i)0]3lars and other trees which 
may grow in the immediate vicinity. 

Still another insect which at times does considerable 
damage to cotton bolls, particularly those which are far 
advanced or have oi)ened, is the red bug or cotton stainer. 
This insect is not known to be jn-evalent except in Florida 
and Georgia and neighboring portions of South Carolina 
and Alabama, The insect does its damage by ])uncturing 
the bolls and sucking the sap, causing them to become 
diminutive or to remain immature. Later, however, the 
insect may enter open bolls, puncturing the seed and dam- 
aging the fiber by its yellowish excretions. 

Grasshoppers 

Grasshoppers are considered one of the most common 
class of insects which do injury to the foliage of the cotton 
plant. Several s])ecies of grassho]i])ers have this habit, and 




THE SMALLER MEADOW GRASSHOPPER 

the list of cotton insects contains the names of fourteen 
grasshoppers which are found upon the plants. The dam- 
age which the grasshopper causes to the foliage of cotton is 
similar to that of the bag woVm and the hickory horn devil. 

The Cotton Stalk-Borer 

Puncturing of the terminal portion of the stalk by 
l^lant bulk occasionally occurs, but is com])aratively rare. 
There is but one borer of the stalks of cotton, and that is 
the long-horned beetle known as the cotton stalk-borer. It 
is occasionally mistaken for a direct enemy of the plant, 

16 



but investigation has shown that it lays its eggs upon, and 
its larva bore into, only such stalks as have been damaged 
by some other cause, such as rust. It follows injury to the 
plant, therefore, rather than causes it. 

There is only one brood of these insects a year, and 
they commonly reach maturity in the middle of August. 




THE COTTON STALK BORER 

(a) larva from above; (6) larva from side; (c) tunneled cotton stalk, showing exit 
hole; (f/) adult beetle. All enlarged except c. 

They frequently pui)ate in the stalk, especially in the case 
of large, hollow stalks, but sometimes burrow a short dis- 
tance into the ground for pupation. The adult is a moth of 
a wood-brown color sprinkled with yellowish dots. It is 
one of the night flyers. The eggs are laid in the early 
si)ring on the stalks attacked. This insect frequently be- 
<'omes abundant enough to do serious damage to plants. 



White Grubs 

The young of the May beetles or June bugs are capable 
of devastating and frequently destroying large portions of 
farm crops by eating the roots. The crops commonly dam- 
aged include two of our most important staples, namely, 
corn and potatoes, but the beetles also attack cotton and 
are often extremely destructive. 

These insects require three years to complete their life 
cvcle, and usually only one l)rood is destructively active in 

17 



a given locality. An abundance of May beetles one year 
forecasts a large growth of grnbs the following season. 

It should be remembered that injury from white grubs, 
as well as from many other pests, may be forestalled by 




WHITE GRUBS 
Showing the 3-Year ] eriod of their cycle life. ' 

the correcting of farm practices ; but after cotton or any 
field croj) has become infested it is imjiossible to prevent 
further injury to that particular crop for the current 
season. 

The Garden Web Worm 

This widely distributed and common insect is espe- 
cially notable because of its occasional outbreak. Its ordi- 
nary food plants are a number of common weeds, especially 
pigweed and purslane, but when these are used up because 




VARIOUS STAGES OF THE WEB WORM. 

of exceptional abundance of the larva, the latter readily 
devour cultivated crops, including cotton. Web worms 
are especially fond of the finer and softer grasses in the 
south, such as butTalo grass and Johnson grass. 

The mature larva, about five-eighths of an inch long, 
are whitish or dusky or even greenish, with black dots. 
They spin a loose but evidently individual web, rarely more 



than one worm occupying the same web. This web incloses 
more or less of the foliage of an infected plant. 

The larva are very active, feigning- death when dis- 
turbed or spinning a thread and dropping to the ground, 
slipping out of sight in crevices or loose earth. Most of 
the feeding is done at night, the larva usually resting in 
the web by day until the last stage, when they are active 
during the daytime. 

Plant Lice 

While the cotton i)lant is yet young and tender, the 
damage which plant lice do by gathering upon the young 
shoots and tender leaves, and curling and distorting them, 
may be very considerable. 

Eecent investiuations have shown that these insects 




COTTON LOUSE 
Cluster of lice on cotton leaf (greatly enlarged) . 

are identical with the species which occurs commonly 
through the south and the north upon melons and cucum- 
bers and which derives its food from a great variety of 
plants besides cotton. 

As the cotton plant grows larger and stronger, the 
work of the cotton ai)hi8 becomes of no imi)ortance, partly 
because of the hardier condition of the plant, but prin- 
cipally because the many natural enemies of the lice in- 
crease to such numbers as nearly to annihilate them. 

The insects are small greenish, bluish, or brownish 
lice, almost unnoticeable except when they congregate in 
clusters on the ])lants, and they are too easily identified 
and too well known to need further description here. 

19 



PART II 
DISEASES 

"To know tlie disease is the coiinnem-t'ineiit of tlie cure." 

Cotton diseases may be classed in three general divi- 
sions according- to their methods of attack: 

First, diseases affecting the leaves only, such as mo- 
saic, or yellow leaf blight, red leaf blight, and angular leaf 
blight. 

Second, diseases which may attack any part of the 
plant ; these include f renching, sore shin, damping off or 
seedling rot, authracnose, root rot, cotton leaf blight, areo- 
late mildew, cotton boll rot, and ripe decay of bolls. 

Third, diseases which injure the roots only, such as 
root galls, knots, etc. 

Soil and Seed-Sick Conditions 

In common with other field crops cotton is subject to 
a number of fungous and bacterial infections which live 
in the soil and seed and which are manifest in various de- 
formations, blights, leaf and stem deterioration, root decay, 
and general sai)ping of plant vitality and inmiaturity or dis- 
ease infection of bolls. 

Such infections are manifested by the rotting of root 
systems and a tendency to re-root above the infected parts, 
by spots and holes on the leaves, by discoloration and de- 
cay of the veins and stems, and by the rotting of bolls and 
locks. 

The infections have been given various local names, 
most of them derived from some characteristic of the in- 
jury inflicted. xVs they will be conunonly encountered under 
such designations, they are here described under those 
titles, all of which might be generally termed soil-sick or 
cotton-sick conditions. 

Cotton Wilt, or Frenching 

The cotton wilt, now widely distributed and yearly 
l^re-em]jting more territory, is caused by a fungus that 
plugs the water ducts in the veins of the stem and cuts off 
the water supply to the parts above, always reducing the 
vii>or of the ])lant and usually causing s])eedy death. Soil 

20 




21 




COTTON WILT 

A row of wilt-i'esistant cotton. Note non-resistant varieties of adjoining rows 

are entirely gone. 



«MW^ . 



-«;. p 




• 'V -'•• , 



>%. . 






ft .iT^ 1. ^Ji.i -Sf - ♦ . 




*^ 



.t.tt^>' 




'i* ■ .T 



^■' 




rfur- 






COTTON WILT 

Cottonfield destroyed by wilt. Note few plants still svn-viving, but these will 
eventually become infected. 

wliicli ])i'odn('es a sick cro]) one year is so infected witL 
the casual fungus as to insure a rea})pearance of the dis- 
ease in more extensive areas in subsequent cro])i)in,i>s. Tlie 
destruction of this disease, which not only takes the crop 



22 



but impairs the usefulness of the soil as well, cannot be 
estimated. Its injnries can be realized only by those who 
have experienced its effects. Wilt lias long been known by 
cotton planters and is now prevalent in many sections 
throughont the whole cotton belt. 

The first appearance of the wilt is a yellowing of the 
lower leaves at the edges or between the main roots, which 
portions may become almost white. Later they turn brown 
and die. A single leaf often presents the three conditions — 
green (healthy), yellow (sick), and brown (dead) — side by 
side in bands parallel to the main ribs and radiating from 
the leaf's stem. The dead parts may break away, leaving the 
leaf ragged. The upper leaves may rapidly pass through 
the same process as the lower ones and soon become af- 
fected over all the plant, leaving only a bare stalk. In mild 
cases, wdiere the disease runs its course more slowly, the 
intervals between the different stages are more prolonged. 
In light sand the disease may progress very rapidly and 
consist of only two stages — the sudden wilted condition, 
then speedy death. The final characteristic of the disease, 
however, as of many other wilts, is the darkening of the 
affected veins, which change from the normal white to light 
brown or black. 

Cotton Anthracnose and Boll Rot 

Anthracnose is a mold-like fungus infection which in- 
vades bolls, stems, seed, and seedlings of cotton. 

When a boll becomes infected, the spores spread rapidly 
through the lint and seed, becoming manifest at first as 
small round spots, dull reddish or grayish black, which 
gradually enlarge until often one-half of the boll is affected. 
Sometimes two or three spots become apparent on a single 
boll, and, as they spread, finally join together in one large 
diseased area, affecting virtually all of the boll. When 
these are cut open, the entire inside is found to be discolored 
or rotten. 

When very young bolls are attacked they are some- 
times" killed outright, while at other times they are dwarfed 
or affected on one side only. Bolls which are not badly 
diseased or those invaded late in their development may 
open an a])parently normal head, but the seed in these dis- 
eased locks is either destroyed completely or so inoculated 

23 




EFFECTS OF ANTHRACNOSE ON THE BOLL 
Cotton bolls infected with anthracnose. 




EFFECT OF ANTHRACNOSE ON THE BOLL 

Cotton boll, showinji only a small spot on the outside, yet the entire lock is 
decayed by anthracnose. 

with the spores as to make them a source of infection in tlie 
succeeding' crop, slionld tliey l)e used for phmting. 

24 



The young i)lants from this kmd of seed are often at- 
tacked and killed by these spores even before tliey reacli 
the surface of the ground. Unfavorable weather causes a 
damping off of the young plants at the ground line. This 
action of tlie infection may be recognized by the dark- 
colored and diseased condition of the stem below the 




EFFECT OF ANTHRACNOSE ON THE BOLL 

A boll of cotton badly diseased with anthracnose and covered with a mass of 

pink spores. 

ground. Cold, dam]) weather in the spring is especially 
likely to cause this, and under such climatic conditions the 
spores of anthracnose are usually |)revalent and destructive. 
Owing to their i)eculiar property of dissolving in water, 
the spores of fungi often become suspended in rain drops 
and are thus carried from infected to uninfected fields by 
rain and wind, and by insects and animals on whose bodies 
they have lodged, having been deposited by drops of rain. 
As the fungi cling to the stalks and live in the ground and 
seed and thus infect fields from year to year, recurrence of 

25 




EFFECT OF ANTHRACNOSE ON THE SEED 

Diseased seedlings caused by anthracnose. 

the disease condition will be noted from season to season to 
the final total failnre of cotton on that particnlar field nnless 
seed selection and crop rotation — to clear the seed and soil 
from the infection — are practiced. 

Angular Leaf Spot 

Angular leaf spot is named from the dark angular 
spots which appear in the. leaves. It is very widespread, 
but rarely appears to such an extent as to attract attention. 
Carefnl observation would x^robably reveal it in every cot- 
ton field during the growing season from May to July and 
frequently later. The disease is first manifested l)y a 
watery appearance in definite spots which are bounded liy 
the veins of the leaves. The spots are sometimes very nu- 
merous and frequently unite into one large area of infec- 
tion. Often the disease follows one or more of tlie nuiin 

26 



ribs of the leaf, being bounded on either side by an ir- 
regular zigzag line. In time the spots become blackish and 
then brown, and are frequently bordered by a blackish color 
where the disease has spread outward from a centrally 
infected spot. 

The dead s])ots in the leaf sometimes break out, leav- 
ing many perforations with ragged edges, somewhat as 
often results in cotton leaf blight ; the disease hastens the 
falling of the leaves. 

In the very earliest appearance of the spots, when the 
watery condition is coming on, these spots swarm with bac- 
teria; these also often occur on the plant bolls which pre- 
sent spots of watery a])])earance, and these finally terminate 
in rot and death. In this case the general weakness of the 
l)lant naturally extends to the boll also. 

Mosaic, Yellow Leaf Blight, or Black Rust 

The first signs of mosaic are yellowish spots which give 
the leaf a checkered ai)pearance. These discolorations oc- 
cur first in small areas, which are roughly rectangular 




MOSAIC DISEASE, OR YELLOW LEAF BLIGHT 
27 



owing to the limitation cansed by the veins and are situated 
at points most remote from the main feeding veins. 

In later stages these weakened areas may be over- 
grown by various fungi. Usually the centers of these spots 
soon turn brown, and the brown parts enlarge and show a 
series of concentric markings. If very dark-colored fungi 
grow upon these spots, they soon become black-coated, and 
from this fact take the popular name black rust, which, 
however, bears no similarity to, or relation with, the rust 
of the cereals. The attack of the fungus causes the pre- 
mature falling of the leaf, thus preventing the proper ma- 
turity of the i^lant. Losses may vary from 5 to 50 per cent, 
and, being widely distributed, such losses are often very 
heavy. It may be safely asserted that this disease cannot 
attack a cotton plant that is in full vigorous growth, but 
a sudden checking of growth and lowering of vitality from 
any cause . will render it liable to serious injury if the 
weather conditions favor the growth of this fungi. 

Frosty Mildew 

The leaf spot caused by frosty mildew is limited 
sharply by the smaller veins, and bears upon the lower 
surface numerous colorless spores upon a colorless coat- 
ing, thus lending a frosted appearance. 




MILDEW OF COTTON 
Showing the spots of mildew on the leaves. 

• 28 



As seen from above the spots are light yellow or of a 
paler green than the normal leaf tissue. Widespread, 
though not especially destructive, frosty mildew does not 
usually attract the attention of the planter, with the re- 
sult that the damage done by this disease is most generally 
said to be due to the attack of some insect, or some other 
disease. 

Red Leaf Blight 

The foliage of cotton frequently presents a red colora- 
tion which is not unlike the red or brown of autumn leaves. 
It is of exceedingly common occurrence toward the matur- 
ity of the cotton, even where the growth is quite healthy 
and rank, but is of rarer occurrence in rich soils than on 
poor land. It is es])ecially common on the drier ui)lands 
where the soil is worn and poor. Here it occurs (|uite early 
in the season, and cotton sometimes makes but little prog- 
ress before the leaves become red. 

Sore Shin, Damping Off, and Seedling Rot 

Sore shin, damping off and seedling rot are names ap- 
plied to a very common disease which causes young i)lants 
to rot off partially or entirely at or near the surface of the 
ground. There seem to be several phases of the disease. 
Sometimes the tissues undergo a soft rot which progresses 
very rapidly, the early stages not being marked by any 
striking color characteristic. 

Primarily the disease is manifested by an ulcerous 
wound upon the stem near the ground, accompanied by red- 
dening or browning of the leaves. If the ulcer enters deep 
into the stem so as to interfere with the stalk, it may cause 
death. This is of unusual occurrence, however, since a 
healing of the wound generally occurs before the disease 
has progressed too far. Infection often results from the 
mechanical injuries caused by tools, the bacteria gaining a 
foothold in these bruised spots, 

Texas Root Rot 

Texas root rot lias been known to attack cotton in very 
destructive forms in Texas, Oklahoma, New Mexico, and 
Arizona, though it has not yet been found east of Texas. In 
the state of Texas in one season alone the damage caused 

25) 



|.\ III! , lIlNOM'^r \\n-. 0:,| III1.iI.mI hI j|i.'l,( >(>(»,( 1(10 r^^^\\\^' I'l.MllIrl 
ITfitll «l It MM M WOl'hiM'IKMII) lIlMII IIk' '"'H \\rr\il 

111 I III'. (lisoMMt* M \\'\\ ol' I ln» phllll . 111,1 \ Will iliul ill \ II I' 
III n »la\ Till' II ii.ilh orciii'. ill or Itrlitrr MnrKcmii!.', ov 
rUNioiuillv upon I'l.iiil . oiih m Irw iik-Iuvm lii^li. Lnlot' iiuinN 
|>l<Ullw HdlVtM ti iiiiildi l(ili\ llii' II' nil Wpiii'.', irro«',iilnr 'pot'. 
ol' lIlHOMHt* III llio lioMs iiiiiilvtMl 1>\ lli>' iMfcnci' ol iinnu'i 
\\\\^ ItOinlini",, (lonti |'l;inl . I'lio I'l.inl . willioi mo'l i;i|Mill\ 




Slu>\\u\^ iKo t\vv>( i\>( v»l »'vvU\\\\ 



on \\kA vIh\s, TolUvwrnK vmw, U\\\ \uA so rMpi^lly \\\ oonruuuHl 
ilrv wonlluM' l''s|H>oiull\ al'lor i\ rnin livinn plauls. sur 
roiuuloil l\\ vlocul oju*s» uu\y show syn>ptou\s oT tl\<> (Hsonst* 
\\\ llio I\mmu ol" wartliko l^uiit^s upv>n tho hiprool. All mI' 
fooloil pUuUs lm\o vlisoastnl ro^>|s markovl by i\\\ iujuroil miuI 
sln'UuktM\ («prool» tuvoiupaiiuHl Uy dopit^ssoil spv>ls whirh 
^rv.Mt Urst, luMHlortnl U\ m ro»i\lish vlisvolorMliou, Tho 
oasuni ruuHU!^ i*^ a^^^* nppnroni l\oro. at l\rs( as a wlulo uu>lo, 
whioh UUtM' turns l>ro\vu v>r yollow nml tiually \iovolo|>s « 
wartlike luMiHloulu\i\ Mularj^oniouls Tiom wliivli now rv»ol^ 



sHO 



nil' pill I'o/tli <)\'\('ii o'-'-iir »)(',•!)■ \\\c tsoi) (^iii'fui('«, Kv<'n tli<' 
lint of l)j<' <lih<'a,s<''l planl J!s aJT<'<'l<'<l, tlx* /IIxts Ix^uji^ wJ<J<u' 
aij<l .spirals f<.'W<?j' a/)<l i»jor<' uti<'V<'n Dian upon lumlWiy 
pjanlh. 'rii« <iiHt^aK« in truly of tlit* Hoi), au'i i\u* <JiH<*aH«<l 
hoi) <'<*ijt<*r« <*ijJarK<^ yumrly, a« in tsojl inf<'<'fi<Hi of oIImt 
plants. 

Cotton Root Knot, or Root Call 

Jioof k/iol of ''ollo/i an'l oili<*r <'rop« i« <'auH<*rl hy niinnt'' 
<'<')\vor»nf- \v|ji<')j bore inlo Dx* rools an'l liv lli<'r<'. 'I'lm 
jrrjlalion of t|j<'jr pr<'s<'n<'<^ r<'«iiltH in Um' formal ion of ir- 
loiiuiny hw<'ilinj<«, or j;<allK, varyinf< in wi'/<' fro//i liny I'li 




mnn' qau^ on Kstn 

\ni'u;'^'Ui(imiy. on i\ii* nniall tooia to knot*s an jn/'lj or rfjor<' ifi 
iliHUidU^t' on tlii^ larj<<? om^>>. 

Ttj<e deie^dUm of cotUm lAania affiudt^A t>y root knot, 
i*xf'ii]ft by an nxanilnHthm of tfjtt rootn, in inii/'l< n<or« <iitifi- 
<'ult tj^an in t|j<> o.sihit i>i wilt, |>jw^aw>l pjuntji ar<^ difetir^/dly 
)stur*ttf>/i, hut not ii\f\n'i*i\H\Ay dafonn^lf nh In wilt, an^l Imv** 




Q 
Q 

Q 

O 



o - 
?'2 






^ I 

ii o 



'-4^..: 






.V 



?* 



32 




33 



a peculiar sickly yellowish-green color on both leaves and 
stem. In times of drought affected plants are the first to 
show the lack of water and may wilt slightly in the middle 
of the day. If snch a plant is pulled carefully or, better, 
dug up with a shovel, the roots will be found to be covered 
with swellings, or galls, from the size of a pinhead to half- 
inch or more in diameter. If one of these knots is broken 
open, numerous pearly white rounded bodies about half the 
size of a small pinhead can often be seen with the naked 
eye. 

"When root knot occurs with wilt, which is often tlie 
case, the symptoms of both diseases are present. The 
plants usually all die or are so badly dwarfed that little 
or no cotton is produced. 

Root knot is essentially a disease of light soils. Al- 
though the disease may occur on heavier soils than wilt, 
yet it is not as a rule serious on soils containing a large 
portion of clay. The jilaces of greatest damage are usually 
light sandy spots or ridges in infected fields. 



34 



PART III 
CONTRIBUTING CAUSES 

"A field requires three things, fine weather, good seed, and 
a good husbandman." 

A grower is often unable to explain why his crop is not 
as hardy or as flourishing as that of his neighbor. The 
answer may be his failure to follow some one or all of the 
simple yet necessary practices of good farming operations. 
His loss may be due to poor cultural methods, failure to 
select seed carefully, too frequent cropping of the land to 
the same thing, improper cultivation, or carelessness in 
some other fundamental. An investigation of methods 
often offers a clear explanation of otherwise inexplainable 
failures. 

Shedding of Bolls or Squares 

The shedding of bolls or squares, or their drying up 
while still attached to the plant, is very frequently encoim- 
tered. This is almost always claimed as hail damage and 
may often be confused with the work of the boll worm or 
with punctures made by some other insect. Sometimes part 
of the shedding is due to the work of the boll worm, but the 
dropping off referred to here is a purely climatic trouble 
or a natural stage of the i)lant's development. 

It occurs most frequently in extremes of either dry or 
wet weather or during the change from one extreme to an- 
other. It may occur to some extent under normal climatic 
conditions, especially if the cotton plants are too thick or 
the variety of cotton is one which develops a very large 
number of bolls in Y)roportion to the leaf surface. 

During a normal period of growth the plants put out 
as many boll forms as would quickly mature should favor- 
able conditions continue. If a very dry period follows this, 
interfering with the supply of nutriment and moisture, a 
partial withholding of tissue-forming material results at a 
very critical period in the life of the boll, thus forcing the 
tissues into an unnaturally matured condition. 

A long rainy season may also cause the young bolls to 
fall, the soil being so saturated with water as to interfere 
with the roots' absorption and to disturb the assimilative 
activity of the leaves. The falling away of the dead im- 

35 




SHOWING RESULTS OF PROPER FARMING 

Thirfty plants grown from selected seed in a well-prepared seed bed and in soil 

of good fertility. 



36 












'\<'^% 



:-. -5.r- 



mM 












tf § 
Ph 






37 



mature bolls and forms when it does occur is a useful pro- 
vision of nature, since the plant is left in better condition 
for the gathering of the crop which does mature. 

"Wlien the cotton is putting on squares or blooming, the 
claimant often contends that hail knocked the squares off, 
when it is a matter of common knowledge that cotton will 
ordinarily throw off two or three times as many squares 
as it will put on bolls. It is as natural for cotton to shed 
its squares as it is for the cherry and apple tree to shed 
their blossoms. 

The more or less complete separation of the squares 
at the line of division between the healthy and dying por- 
tion depends upon the point of attachment of the bloom 
to the stem, and f6r this reason they sometimes remain at- 
tached to the plant though withered and lifeless. 

Climatic Conditions 

During all stages of its growth the cotton jilant is sub- 
ject to destruction by various climatic conditions, each of 
which resembles hail damage very closely. Unless an ad- 
juster is familiar with these and prepared to ascertain the 
true cause of the damage, a dishonest claimant will use 
every effort to convince the adjuster that these are losses 
for which he should be paid under his hail contract. 

Sand Storms 

When the tender plants have pushed their way out of 
the ground and before they have become hardy enough to 
withstand such damage, the action of the wind sifting sand 
across the land will completely cut off young plants and 
often cause total losses to entire fields. On close examina- 
tion the shifting of the sand and the conseciuent damage 
caused can be plainly pointed out to the claimant contend- 
ing for an unfair allowance. 

Action of Rain 

Hard, beating rains, accompanied by high winds, will 
also cut off the tender plants, and a claimed hail loss is 
the inevitable result. Unusual care must necessarily be 
exercised in the adjustment of such losses to separate this 
loss properly from that actually caused by hail. Another 

38 



effect of beating rains is to pack the sandy soil too firmly 
aronnd the yoimg cotton plant, "choking" it off and re- 
tarding or totally stopping the growth of the stalk. In 
either event a sickly stalk or a dead one results. 

When the plant is more mature and the bolls open, a 
hard rain will cause the cotton to shred out and hang in 
strings from tlie plant. Such injury often resembles and 
has been erroneously claimed as hail damage. The present 
form of "Open Cotton" clause excluding liability after the 
bolls have opened was adopted on this account. 

Seed Selection for Cotton 

But few crops are as susceptible to material loss from 
lack of proper seed selection as is cotton. The inevitable 
results of indifferent methods of seed selection are mani- 
fest in a sickly stalk, fungous infection, inferior quality, 
and subnormal yield. 

Where some system of careful selection is not prac- 
ticed by the grower, such conditions are almost always 
evident in the growing crop. A great variation is always 
noticeable in such fields, one stalk having a large number 
of bolls, while another, growing by its side, will be almost 
barren. 

If a seed-breeding plat is kept by the grower, isolated 
from the general fields to prevent an intermingling of pol- 
len and possible fungous infection or insect infestation, and 
careful elimination is made thereon from year to year, the 
results are bound to show in the field, and the higher grad- 
ing of i3lants thereby obtained will eliminate the cause of 
many illegitimate claims now made for hail damage. 

The use of adapted seed instead of the imported va- 
riety results in a stronger, healthier growth of cotton which 
is less affected by either hail or other climatic or disease 
conditions. 

There is one source of infection of cotton seed that is 
not applicable to any of the other crops, and that is the 
danger of impurities or fungi becoming mixed with the seed 
when it is ginned. In many places a special device is in 
use by the ginner to guard against infection or mixing of 
seed, but, even with such precaution, carelessness in clean- 
ing the saws will inoculate the seed cotton with anthracnose 
or other bacterial disease. The grower who has selected his 

39 



seed and had it ginned in a presumably clean gin is nnable 
to believe that the resultant loss is due to any other cause 
than a hailstorm. Inquiries as to methods of seed selection 
and ginning are never out of order if the loss appears to be 
due to a fungus infection or ])oll-rot condition. 

Crop Rotation 

To restore the necessary quantity of organic matter 
to the soil, a system of rotation is essential. Where some 
proper cropping scheme is not followed, poor yields, total 
failures, or disease-infected iields are commonly encoun- 
tered regardless of the fact that cotton is one of the few 
crops that does not exact a heavy annual toll from the soil. 

Cotton can be planted more years in succession on 
the same plot of ground without completely depleting the 
fertility than can, possibly, any of the other staple crops; 
yet extended cropping of cotton will in time wear away the 
best soil or permit it to become fungus-ridden. When any 
form of fungus infection has gained a footing, rotation is 
the only means of elimination of this soil-sick condition. 

The depleted field is the first to show the effects of un- 
favorable climatic conditions, and deficiencies of moisture 
are first seen in a field that has long been planted to cotton 
alone. 

Losses from Deep Cultivation 

While normally the cotton plant has a strong, branch- 
ing taproot penetrating deeply, the root system is subject 
to much modification, owing to the nature of the soil and 
the subsoil. In many instances the taproot may be absent, 
while in other instances a well-developed ta])root has often 
been traced in sandy soil and subsoil to a depth of two to 
three feet without coming to its end. In heavy clay loam 
only one plant out of twenty-one was found which had a 
well-developed taproot over 9 inches long. In either kind 
of soil the lateral roots begin about 3 inches below the sur- 
face of the soil and spread out in all directions, most of them 
being within 9 inches of the surface. Most of the lateral 
roots originate at li to 2 inches below the surface of the 
ground, and their direction is such that deep cultivation 
would break a large proportion of the roots. 

Losses caused by too deep cultivation of the cotton 

40 



plant are often attributed to some other cause of damage. 
T]ie sickly appearance of a plant whose roots have been 
broken by a cultivator shovel closely resembles damage 
caused by insects working on the roots, by cotton-sick soil, 
or by lack of moisture, and hail is quite frequently blamed 
for such conditions. When hail damage is claimed on cotton 
plants that have a wilted appearance, it is well to examine 
tlie soil to determine the depth of the preceding cultivation. 



41 



•^ -*^ 







■^ 












Ci 






o 






« 












-D 






c3 






to 






TS 






O 






tC 






T3 






01 












c3 






> 




































O 


-% 




>. 


o 










o 


^ 




a 


ci 







■*"" 




&H 








~^ 


m 




C3 


O 


M 


C^ 


O 


J2 














r/1 


■c 


"tJ 


O 


o 


T5 


M 


o 


=5^ 








>, 


T3 


-C O 


ri 




o j; 








O 


O 


1-4 '^^ 


^ 


>. 


&-S 




O 




o 


a 




p:| 


W 


PU 



-C O ^ 



>.5 















































~S, 












.-- 
















M 
















j2 




(H 




























=;; 




c 












j3 

















T* 




c 












IS 


















































































>H 





a 


£ 










10 


C 
t3 




"3 


'S 








^ 




•C 


^ 


> 










(3 






OJ 


-r 






s 


S 





< 


-C 


a 




i2 


cj 







>> 




■^ 





a 

c3 





M 


"3 


T3 

-d 
a 
3 


c3 




■3 


3 

J3 





3 


3 


















-* 


•7- 


.^ 


■i-H 


"O 


" 


c 


,0 


^. 




5 


?= 





^' 





t: 


"S, 





'>3, 


a 

tc 














"3 > 








03 


>. 






5 


i.s 


0) 
0) 




3 
M 
3 


< 


"^ 


h-1 


^ 


hJ 


1-1 





< 



C H 











^ 




-a 





















3 
















>> 






































'rl 














s 










Sh 


















0; 




OJ 


























CO 






a. 






cc 


















tc-C 


C 


a; 


















cS 
















> ^- 












^ 


> 




^ 


Ph 




















C; 





c 


•n 





> 


m 
a; 
> 








3^ 




3^ 


c3 


s3 


cS 


3 


C 







3 








<D 















w 





>A 


a 


h-1 



S3 -a 



OS—- 
O 









hJ B 

u 
1-:! 



3 3 
O O 



O 






s«« 






.3 > TS 
m e3"0 t. 
O; O f5j5 s< 

•qM C3CEI-1 



SXOOH 

OX sassoi 



saAvai ox sassoi 













SC 














■^ 





















■ ^ 




jd 










5 








^^ 












>i 






































"^ 











;5 








"C 

















i-. 











0; 




















tj 


^ 


M 




hJ 






tc 



















a3 


:3 


"o 






























S 


pa 













a 








S 




















^ 

























"c3 




C' 


I-' 

_o 












_e3 








"3 










2 

2 


h^ 


c 








tjC 














Si 


O 






c 


Si 




tc 


"03 




.p 














-♦— 


H-^ 






3 


o 


t3 




i 
'03 


3 




^5^ 






-c 








s 

0) 


o 


-c 


o 




2 





03 




G 5 


bj. 














Si 


|3 


O 


O 
M 


^ 


o 


~ 


01 


2 


y: 


g 


JS£ 


-73 




M 








^ 


03 


p 


M 


O 


n 


p 




^ 


PL, bi 


^^_j 




.^ 








Si 


< 

Pi 

< 

Ph 
Ph 

<: 


s 




03 

£ 

03 

2 

O 


"o 




a 


oi' 



0; 






0: 

^"03 

"2 "^ 


"a 

c3' 


w 


0) 



;-, 




G 

-a 



0) 


c3 
M 


o3 


_a 






OS 


3 


— 


p 


"0 


=; 


^ 





3.2 


^ 


-0 

"2 


>ii 




3 


-a 


fci 




o 




c 

m 

o 


3 

o 


PQ 







3 
"a 


c c 


03 




2 

to 
Oi 


L^ 


>» 


tc 

_3 




Si 


Cj 
















o3 


3 


T3 >< 














CO 

o3 


_S 


a 





3 


-2 


M 


'^1 

a£ 





Ti 



'H Si 
0.2. 

t; c" 







"3 


M 




"o 


0) 


2 


2 


3 


"3 


^ 




C 


■^ 


O"^ 


^ 


c 


c 




« 




Si 


a; 


6 


^ 


pa 


U 


H 


Pi 


^ 





X 





D 


K-l 




:;:3'T3 






_c 




















-a 








r* -^ 
























c 








^ 1^ 


























03 








0) rf 
































Q 

o 

K 


pqpq 

S <^ S 


C 
O 

O 

"c 




iH CO 
03^ 

ate 


PQ 


C 







c 

03 

s 





;h 

c3 
0; 
C 





C 




tc 


Pi 

Sh 

03 






tc 

"3 

tc 


t« 





o3 "^ 3 


ffi 


o 

0) 


^1 





"o 




a; 
c3 






C 




3 





c 



^ 




^ 


> o c- 


s 
'S 


> 

03 
lU 


r-.~ 




a 


pa 

a 




pa 


CC 


'■3 


c 











03 






h^l 


^ 


h-l 










< 


►^ 


(^ 
















^ 




o3 






f-i 


















1 










c3 








fcC 


















_o 








04 
O 


o 






pa 














^ 


fcC 

03 




C 

03 


'm 


To 


to 
T3 

a 


W 


_o 




2 


u 


S 


JB 




2 


2 


IS 





3 


el 
3 


3 


3 



o 
o 


KB 


c 




pa 


~o 

pa 




^ 





"2 






^3 








l_] 


^ 






M 


•c 











3 




3 




_ o 
1^ 


03 
> 


03 


_C 


aj 




03 
> 


03 




> 


^ 


S 


IB 
4J 


m 


g 








tH 


;-< 


so 









k. 






fH 



















03 
1-5 




^ 




C4 


a 




^ 


hJ 


c. 


03 


Q 




a 

CO 


a 


5 








-2 
03 
O 




c 

03 










E3 






> 










3 


Q 


— 




M 


0; 
C 


9 





ii 





pa 





„ 


"3 








03 


Si 






> 

o 
o 

^ 


in 





(DM 

a 


o3_ 




■2 te 

pq 

M 03 









a 


1 



a 
C 




3 


in 


1° 




"o 


"S 




1^ 




11^^ 


C 



S 


"c 


■=;.2 

2 *" 
1— 1 


1 


3 


0*^ 


£.2 




m 


« 


i-J 


CO 


^ 


< fe 








^ 


^ 


t^ 


0:; 


rh 


H W 


































tf o 


^ , 
































Oi^< 


CDiS 














b£)+- 


















HOg 


35 
































<; < 


•^ffi 














'*';r 


















^ Q 














Q^ 




















qr- 


[0 


a 


I s:e 


[SSC 


)T 






\ 


n 


"f^l 


S 


X s: 


ISSC 


)T 





.2 C 



"3 


y5 




03 









-^ 


1 f 


hfl 














3 


03 


re 







3 



















S^ 


-;i 











01 



o o 



o3 ^ 

o 5 






2 ^ 

:a .2 tc 
o 03 



01 o3 



ic (U 

o . 
a-o 



O O 



"A single fact is worth a shipload of argument.' 



44 



INDEX 

No. 

A One-Crop Farm (Illustration) 33 

Angular Leaf Spot - - 26 

Boll Weevil, The —- -- --- 9 

Climatic Conditions - 38 

Correct Methods Did This (Illustration) 32 

Cotton Anthracnose and Boll Rot — 23 

Cotton Boll Weevil (Illustration) -- 9-10 

Cotton Boll Worm, or Corn Ear Worm, The 11 

Cotton Cutworm, The (Illustration) -— — . 8 

Cotton Leaf Worm, The Cotton Army Worm, or Cotton Cater- 
pillar 12 

Cotton Louse (Illustration) . - 19 

Cotton Root Knot, or Root Gall 31 

Cotton Root Rot (Illustration) 30 

Cotton Stalk Borer, The -- 16 

Cotton Stalk Borer, The (Illustration) - 17 

Cotton Wilt (Illustration). _____ 22 

Cotton Wilt, or Frenching 20 

Crop Rotation ___ ______ — 40 

Cutworm, The _ 8 

Effect of Anthracnose on the Boll (Illustration) .24-25 

Effect of Anthracnose on the Seed (Illustration) 26 

Frontispiece 2 

Frosty Mildew _ _. 28 

Fungous Infection Caused This Failure (Illustration) ___ 21 

Garden Web Worm, The 18 

Grasshoppers_ 16 

Insects Injuring the Boll _____ - 15 

Introductory - 7 

Leaf -Feeding Caterpillars - 14 

Leaf Roller (Illustration) 14 

Losses From Deep Cultivation___ _____ 40 

Mildew of Cotton (Illustration) 28 

Mosaic Disease, or Yellow Leaf Blight (Illustration) 27 

Mosaic, Yellow Leaf Blight, or Black Rust______ ___ __ 27 

45 



INDEX— Continued 

Page 

No. 

Part I — Insects 8 

Part II— Diseases .-. 20 

Part III — Contributing Causes 35 

Plant Lice 19 

Red Bug or Cotton Stainer, The (Illustration). 15 

Red Leaf Blight 29 

Root Galls or Knots (Illustration) 31 

Seed Selection for Cotton ...._ 39 

Shedding of Bolls, or Squares 35 

Showing Results of Improper Farming (Illustration) 37 

Showing Results of Proper Farming (Illustration) .-- 36 

Smaller Meadow Grasshopper, The (Illustration) -. 16 

Smartweed Caterpillar, The (Illustration) 13 

Soil and Seed-Sick Conditions- -— — 20 

Sore Shin, Damping Off, or Seedling Rot -— 29 

Summary of Losses to Cotton __.. 42-43 

Texas Root Rot 29 

Transformation of Cotton Boll Worm (Illustration) 11 

Various Stages of the Web Worm (Illustration) -.. 18 

White Grubs- 17 

White Grubs (Illustration) 18 

Zebra CaterpiUar, The (Illustration) 14 



46 



LIBRARY OF CONGRESS 



002 811 533 7 



